中文摘要：

为了改进青藏高原东北部土壤湿度的观测和模拟效果,利用AMSR-E（Advanced Microwave Scanning Radiometer-EOS）亮度温度资料,估算了高原东北部的土壤湿度值;还利用耦合了Noah陆面模型的WRF中尺度模式WRF-Noah,结合牛顿松驰逼近同化法对AMSR-E估算的土壤湿度进行了同化试验。结果表明：与实测及NCEP再分析值土壤湿度相比,估算的高原东北部的土壤湿度值虽小些,但能够体现土壤湿度随降水事件等的影响。使用牛顿松弛逼近法同化后比没有同化或采用直接替代法模拟的土壤湿度的效果要好。在区域尺度上,通过对牛顿松弛逼近法中质量因子的详细控制,采用该同化方法后对沙漠地区土壤湿度的模拟改善最为明显,其次是草地以及灌木丛与草地混合区;在时间尺度上,采用牛顿松弛逼近同化方法后模拟值与实测值的均方根误差得到减少。

英文摘要：

An estimation model of soil moisture from the AMSR-E brightness temperature data was coupled into the WRF-Noah mesoscale numerical model for improving the observation and model simulation ability of soil moisture over Northeast Plateau.The main condusions are as follows： Firstly the land surface soil moisture（SM） in the northeastern part of the Qinghai-Tibet Plateau was estimated by the AMSR-E brightness temperature data.Its value was something lower than the observed and the NCEP reanalysed data,but regional distribution was reasonable and the temporal variation showed a quick response to the daily precipitation.Sencondly,the estimated SM was assimilated into the WRF-Noah model by using the Newtonian relaxation assimilation method.By fine tuning of the quality factor in the Newtonian relaxation method,the simulated SM values were obviously improved in desert areas,somewhat improvements also occurred grassland,shrub and grass mixed zones.On temporal scale,the difference between the simulated and observed SM were also decreased.